The invention relates generally to electrocardiograms (ECGs) and the use thereof, and more particularly to, a method and apparatus to remotely monitor patients using a portable ECG device with a wireless communication interface.
ECG analysis is a well established method for studying the function of the heart and identifying disorders of the heart. An ECG is a graphic tracing of the variations and the electrical potential caused by the excitation of the heart muscle as detected at the body surface by the leads of the ECG device. A normal electrocardiogram is a scale or representation that shows deflections resulting from cardiac activity as changes in the magnitude of voltage and polarity over time and includes a P-Wave, a QRS complex, a T-Wave, and a U-Wave. These waves are then analyzed using a set of rules and parameters to determine what is normal and what is not. Certain deviations are used to flag possible complications.
ECG is an important tool in diagnosing patients presented to an emergency room with chest pain. One particular disorder that is studied using ECG is acute cardiac syndromes (ACS), which includes, but is not limited to, acute myocardial infarction (AMI) and acute cardiac ischemia (ACI), the latter of which is commonly referred to as unstable angina. Acute ischemia, or unstable angina, includes the starvation of oxygen to a portion of the heart, commonly caused by a partial blockage, and acute infarction is the complete blockage of oxygen to a portion of the heart. Ischemia can lead to or be a symptom of myocardial infarction. It is well known that time is critical in diagnosing these conditions in a patient experiencing chest pain.
Unstable angina, or ischemia, is sometimes difficult to diagnose and differentiate from other causes of chest pain which are not life threatening. However, since ischemia can lead to AMI, and since time to treatment is critical once AMI sets in, it is advantageous to properly diagnose an ischemic patient as soon as possible. For example, once AMI sets in, the benefit of applying treatment is reduced significantly when the elapsed time from the onset of AMI chest pain to treatment exceeds six hours. Unfortunately, patients often delay in seeking treatment when they first experience chest pain, which compromises the opportunity that exists for salvaging the heart muscles affected via treatment, such as thrombolytic therapy. Further exasperating this problem, studies have shown that patients who are under the care of a physician, and/or have previously experienced AMI, delay the most in seeking care. This may be due to the fact that the patients do not wish to “bother” the physician for “mild” pain. It may also be due to the fact that the patients may have had false alarms in the past that resulted in a long wait at the hospital.
It would therefore be advantageous if a physician, or health care provider, could supply a device to this type of patient that could expedite diagnosis and treatment by alleviating the embarrassment and time expense of showing up in an emergency department when in fact, no cardiac problem exists. This could eliminate not only the time involved in a patient going to the emergency room for indigestion, but also saves hospital resources and health insurance costs.